摘要
利用2016—2018年常州市区环境空气细颗粒物数据,结合同期地面气象资料,分析了常州市区PM 2.5以及气象因素的变化特征,并统计分析气象因素对PM 2.5浓度的影响。结果表明:常州市区PM 2.5、降水量、相对湿度和气温等具有明显季节性,呈夏季较高冬季较低,而气压夏季较低冬季较高的特征。相对湿度与PM 2.5呈正相关,即随着相对湿度的增加PM 2.5超标率和平均浓度均增加;降水对PM 2.5具有一定的清除作用,清除率与降水前PM 2.5浓度、降水量、降水强度有关,降水量、降水强度越大,则降水清除效果越好,而降水前PM 2.5浓度较小,则清除率不明显;常州市区偏西风时PM 2.5的超标率和平均浓度较其他风向较高;风速对常州市区PM 2.5的影响呈负相关,即风速越大PM 2.5超标率和平均浓度均减小;常州市区地面天气形势可以分为两种类型,第一种类型表现为气压较低气温较高,PM 2.5超标率以及平均浓度相对较低,而第二种类型表现为气压较高气温较低,PM 2.5超标率以及平均浓度相对较高。
Variations of PM 2.5 mass concentrations and meteorological factors and the impact of meteorological factors on PM 2.5 concentration in Changzhou urban areas were analyzed based on observational data of airborne fine particulate matters and meteorological elements near the surface from 2016 to 2018.The results indicated that obvious seasonal variations are observed in PM 2.5 mass concentrations,precipitation,relative humidity,temperature,and other meteorological factors in Changzhou urban areas,with higher values in summer and lower values in winter except for air pressure.PM 2.5 concentrations have a positive correlation with relative humidity,and PM 2.5 exceeding standard rates and its mean concentrations increase with the increase of relative humidity.Precipitation has a scavenging effect on PM 2.5 on some degree,which depends on PM 2.5 concentrations before precipitation,precipitation amount and intensity.Larger precipitation amount and intensity usually result in a better scavenging effect on PM 2.5.While the scavenging rate is small when PM 2.5 concentration is low before precipitation.PM 2.5 exceeding standard rates and average concentrations are higher in presence of westerly winds than other wind directions.PM 2.5 concentration has a negative correlation with wind speed.PM 2.5 exceeding standard rates and average concentrations decrease with stronger wind speeds.Ground synoptic situations in Changzhou urban areas can be divided into two types.One type is characterized by low air pressure,high temperature,and low PM 2.5 exceeding standard rate and average concentration,and the other type with high air pressure,low temperature,and high PM 2.5 exceeding standard rate and average concentration.
作者
王振
杨卫芬
叶香
李艳萍
夏京
李春玉
何涛
WANG Zhen;YANG Wei-fen;YE Xiang;LI Yan-ping;XIA Jing;LI Chun-yu;HE Tao(Changzhou Environmental Monitoring Center of Jiangsu Province,Changzhou 213001,China)
出处
《气象与环境学报》
2020年第3期26-32,共7页
Journal of Meteorology and Environment
基金
江苏省常州环境监测中心培优、培新科研项目(201810-PX)资助。
关键词
气象因素
PM
2.5超标率
清除率
天气形势
Meteorological factors
PM 2.5 exceeding standard rate
Scavenging rate
Synoptic situation
